System and method for treating a borehole

ABSTRACT

A method for treating a borehole or formation including creating a hydrodynamic barrier in a selected location, treating a target in the borehole with a treatment fluid, and maintaining or directing the treatment fluid with the hydrodynamic barrier. A system for treating a borehole or formation. A barrier system including a rotatable member, a tubular disposed in radially spaced relationship to the rotatable member and defining an annular space between the tubular and rotatable member, the rotatable member configured to rotate at an RPM relative to the tubular sufficient to establish circular fluid movement in the annular space.

BACKGROUND

In the resource recovery industry, many operations are necessary in the downhole environment. These include borehole and/or formation treatment operations that often require barriers be available to direct or contain various treatments to target areas. Treatments include stimulation treatments such as fracturing, acidizing, etc.

Barriers include packers, and other types of seals and valves that are ubiquitous in the industry and function reliably and consistently but still may have drawbacks for certain wells or applications. Such drawbacks may be in the form of cost or may be in the form of ancillary structure needed to create the barrier in a situation where that structure presents its own inherent hurdles to overcome, for example.

The art therefore would well receive alternative systems and methods that facilitate borehole and formation treatment while avoiding drawbacks of current solutions.

SUMMARY

A method for treating a borehole or formation including creating a hydrodynamic barrier in a selected location, treating a target in the borehole with a treatment fluid, and maintaining or directing the treatment fluid with the hydrodynamic barrier.

A system for treating a borehole or formation including a rotatable member, a tubular disposed in radially spaced relationship to the rotatable member and defining an annular space between the tubular and rotatable member, the rotatable member configured to rotate at an RPM relative to the tubular sufficient to establish circular fluid movement creating a barrier in the annular space, and a treatment fluid volume in operable communication with the barrier.

A barrier system including a rotatable member, a tubular disposed in radially spaced relationship to the rotatable member and defining an annular space between the tubular and rotatable member, the rotatable member configured to rotate at an RPM relative to the tubular sufficient to establish circular fluid movement in the annular space.

BRIEF DESCRIPTION OF THE DRAWINGS

The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:

FIG. 1 is a schematic view of a casing a rotating element illustrating a location of a hydrodynamic barrier during relative rotation of the rotating element and casing;

FIG. 2 is a schematic view of a borehole with a workstring disposed therein to create a hydrodynamic barrier and supply treatment fluid; and

FIG. 3 is a schematic view of an alternative configuration that generates two hydrodynamic barriers in spaced relation to one another to segregate a target zone.

DETAILED DESCRIPTION

A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures.

Referring to FIG. 1, a barrier system 10 is schematically illustrated. The system 10 includes a rotatable member 12 and a tubular 14 radially spaced from the rotatable member 12 to define an annular space 16 therebetween. The tubular 14 may be the borehole wall, a casing, or another tubular form disposed within the casing. The rotatable member 12 is driven by a motor 18 that may be a mud motor, electric motor or other configuration capable of imparting rotational torque to the rotatable member sufficient to induce in the rotatable member 12 an RPM (revolutions per minute) that will result in a hydrodynamic barrier in the annular space 16. Exactly what RPM that is depends upon viscosity of the fluid within the annular space 16, the radial dimension of the annular space 16, and the geometric conditions in the particular annular space 16 such as radial runout and surface roughness. It will be appreciated that for borehole equipment, it is likely that the tubular 14 may be an “as rolled” casing with runout approaching 0.125 inches in places. This will induce turbulence in fluid moving in the annular space and make generating a laminar circular flow therein more difficult and require more energy to do so. In embodiments, it is contemplated that the annular space will have a range of radial dimension from 0.002 inch-0.75 inch. With increasing viscosity fluids the radial gap may be larger. With this geometry and considering an embodiment where the fluid will be drilling mud, the RPM required, which is also related to viscosity of fluid employed (higher the viscosity, the lower the required speed), for the rotating member 12 is up to about 10,000 rpm. Employment of the Sommerfeld Number and associated equation will also be of use in determining parameters for particular embodiments.

In order to achieve the RPM necessary, some embodiments of the hydrodynamic barrier will require a gear train, not shown but understandably operably disposed between the motor and the rotatable member 12.

Referring to FIG. 2, a first embodiment of a system for treating a borehole or formation 30 is illustrated. The system includes a borehole 32, which may be cased or open hole, the line indicating the borehole 32 being intended to represent both, and a work string 34 disposed therein. The work string includes a barrier system 10 therein. In the illustration, the system 10 is disposed at a downhole end of the string 34 but it may also be placed in other locations of the string 34. The work string 34 in this embodiment includes a central bore 36 configured to deliver fluid to an end 38 of the work string 34. The fluid may be a treatment fluid 40 such as a fracturing fluid, an acidizing fluid, etc. The barrier system 10, being activated to create a hydrodynamic barrier 42 maintains the treatment fluid 40 downhole of the hydrodynamic barrier 42. In the event acid is being used, the barrier may be employed to prevent the contamination of component uphole of the barrier 42 with acid. In such a case, the barrier created may only be one configured for 1000 psi-3000 psi differential pressure. In a case where the treatment fluid 40 is a fracturing fluid, and hence great pressure is to be applied to the fluid, the barrier 42 may be configured for 10,000-15,000 psi differential pressure. As noted above the configurations are driven by fluid viscosity within the barrier 42 and RPM of the rotatable member 12.

Referring to FIG. 3, another embodiment of a system for treating a borehole or formation 50 is illustrated. In this embodiment many of the components are the same as the embodiment illustrated in FIG. 2. For the sake of brevity, just the distinction is discussed. As illustrated, instead of one rotating member 12, there are two rotating members 12. Each of the members 12 work identically to those described in the foregoing and indeed they may be powered by the same motor. They are spaced from each other in order to create a segregated area 52 of the borehole 32 within which the system 50 will provide treatment fluid 40. The benefit of this embodiment is that barriers 42 are created uphole and downhole of the target area 52 thereby providing greater directional control of the treatment fluid 40 and a smaller potential volume in which fracture fluid need be pumped in a fracturing operation.

In each of the embodiments, the barrier created is temporary in that it exists (greater or lesser pressure differential capability dependent on rotational speed, gap dimension and viscosity) on while the rotatable member 12 is rotating sufficiently quickly to generate a circular fluid movement and accordingly the barrier. Hence, for methods of use of the system, the motor 18 will be activated to rotate the rotatable member 12 at an appropriate speed for the application and parameters related to the Sommerfeld Number. Once the hydrodynamic barrier (or seal) is established, the treatment fluid 40 is pumped to the target location to effect the desired treatment. After treatment, the motor may be turned off and the barrier 42 will simply cease to exist.

Set forth below are some embodiments of the foregoing disclosure:

Embodiment 1

A method for treating a borehole or formation including creating a hydrodynamic barrier in a selected location, treating a target in the borehole with a treatment fluid, and maintaining or directing the treatment fluid with the hydrodynamic barrier.

Embodiment 2

The method as in any prior embodiment wherein the creating is by rotating a member of a work string relative to another tubular form spaced therefrom at a sufficient RPM to establish circular fluid movement in an annular space defined between the rotating member and the another tubular form.

Embodiment 3

The method as in any prior embodiment wherein the rotating RPM is proportional to a radial dimension of the annulus.

Embodiment 4

The method as in any prior embodiment wherein the treating is fracturing.

Embodiment 5

The method as in any prior embodiment wherein the treating is acidizing.

Embodiment 6

The method as in any prior embodiment wherein the hydrodynamic barrier restricts fluid movement past the barrier.

Embodiment 7

The method as in any prior embodiment wherein the maintaining or directing is containing a pressure differential.

Embodiment 8

The method as in any prior embodiment wherein the pressure differential is 1000 psi-3000 psi.

Embodiment 9

The method as in any prior embodiment wherein the pressure differential is 10,000-15,000 psi.

Embodiment 10

A system for treating a borehole or formation including a rotatable member, a tubular disposed in radially spaced relationship to the rotatable member and defining an annular space between the tubular and rotatable member, the rotatable member configured to rotate at an RPM relative to the tubular sufficient to establish circular fluid movement creating a barrier in the annular space, and a treatment fluid volume in operable communication with the barrier.

Embodiment 11

A barrier system including a rotatable member, a tubular disposed in radially spaced relationship to the rotatable member and defining an annular space between the tubular and rotatable member, the rotatable member configured to rotate at an RPM relative to the tubular sufficient to establish circular fluid movement in the annular space.

Embodiment 12

The barrier system as in any prior embodiment wherein the rotatable member is radially inwardly disposed of the tubular.

Embodiment 13

The barrier system as in any prior embodiment wherein the system further comprises a motor connected to the rotatable member.

Embodiment 14

The barrier system as in any prior embodiment wherein the motor is a mud motor.

Embodiment 15

The barrier system as in any prior embodiment wherein the motor is an electric motor.

Embodiment 16

The barrier system as in any prior embodiment wherein the system includes a gear train and a motor configured to produce rotation in a range of up to 10,000 RPM.

Embodiment 17

The barrier system as in any prior embodiment wherein the circular fluid

The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Further, it should further be noted that the terms “first,” “second,” and the like herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The modifier “about” used in connection with a quantity is inclusive of the stated value and has the meaning dictated by the context (e.g., it includes the degree of error associated with measurement of the particular quantity).

The teachings of the present disclosure may be used in a variety of well operations. These operations may involve using one or more treatment agents to treat a formation, the fluids resident in a formation, a wellbore, and/or equipment in the wellbore, such as production tubing. The treatment agents may be in the form of liquids, gases, solids, semi-solids, and mixtures thereof. Illustrative treatment agents include, but are not limited to, fracturing fluids, acids, steam, water, brine, anti-corrosion agents, cement, permeability modifiers, drilling muds, emulsifiers, demulsifiers, tracers, flow improvers etc. Illustrative well operations include, but are not limited to, hydraulic fracturing, stimulation, tracer injection, cleaning, acidizing, steam injection, water flooding, cementing, etc.

While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited. 

1. A method for treating a borehole or formation comprising: creating a hydrodynamic barrier in a selected location; treating a target in the borehole with a treatment fluid; and maintaining or directing the treatment fluid with the hydrodynamic barrier.
 2. The method as claimed in claim 1 wherein the creating is by rotating a member of a work string relative to another tubular form spaced therefrom at a sufficient RPM to establish circular fluid movement in an annular space defined between the rotating member and the another tubular form.
 3. The method as claimed in claim 2 wherein the rotating RPM is proportional to a radial dimension of the annulus.
 4. The method as claimed in claim 1 wherein the treating is fracturing.
 5. The method as claimed in claim 1 wherein the treating is acidizing.
 6. The method as claimed in claim 1 wherein the hydrodynamic barrier restricts fluid movement past the barrier.
 7. The method as claimed in claim 1 wherein the maintaining or directing is containing a pressure differential.
 8. The method as claimed in claim 7 wherein the pressure differential is 1000 psi-3000 psi.
 9. The method as claimed in claim 1 wherein the pressure differential is 10,000-15,000 psi.
 10. A system for treating a borehole or formation comprising: a rotatable member; a tubular disposed in radially spaced relationship to the rotatable member and defining an annular space between the tubular and rotatable member, the rotatable member configured to rotate at an RPM relative to the tubular sufficient to establish circular fluid movement creating a barrier in the annular space; and a treatment fluid volume in operable communication with the barrier.
 11. A barrier system comprising: a rotatable member; a tubular disposed in radially spaced relationship to the rotatable member and defining an annular space between the tubular and rotatable member, the rotatable member configured to rotate at an RPM relative to the tubular sufficient to establish circular fluid movement in the annular space.
 12. The barrier system as claimed in claim 11 wherein the rotatable member is radially inwardly disposed of the tubular.
 13. The barrier system as claimed in claim 11 wherein the system further comprises a motor connected to the rotatable member.
 14. The barrier system as claimed in claim 13 wherein the motor is a mud motor.
 15. The barrier system as claimed in claim 11 wherein the motor is an electric motor.
 16. The barrier system as claimed in claim 11 wherein the system includes a gear train and a motor configured to produce rotation in a range of up to 10,000 RPM.
 17. The barrier system as claimed in claim 11 wherein the circular fluid movement is a hydrodynamic barrier, in use. 